JP3444184B2 - Construction method of parent-child shield excavator and shield tunnel using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parent-child shield machine and a method for constructing a shield tunnel using the machine.

[0002]

2. Description of the Related Art A parent-child shield in which a shield tunnel having a different diameter is continuously constructed by incorporating a child shield inside a parent shield, excavating the parent and child shields integrally, and then excavating only the child shield. The construction method of the excavator and the shield tunnel using the excavator is known.

This kind of parent-child shield machine is, for example,
It is disclosed in Japanese Examined Patent Publication No. 2-44996, Japanese Unexamined Patent Publication No. 5-10086, Japanese Unexamined Patent Publication No. 8-82187, and the like.

In the shield machine disclosed in these publications, the child shield is concentrically arranged inside the parent shield, and if necessary, the child shield is coaxially or axially eccentric with the parent shield. However, the parent-child shield excavators disclosed in these publications have the technical problems described below.

[0005]

That is, in the parent-child shield excavator disclosed in the above publication, the propulsion mechanism of the parent shield and the propulsion mechanism of the child shield are individually provided, and the structure is very large. It's getting complicated, especially when the parent shield is separated from the child shield,
Since it is left in a buried state, including its propulsion mechanism,
There are also economic disadvantages.

By the way, when constructing a shield tunnel with a parent-child shield machine, there are cases where construction is carried out, for example, in a place where the soil cover gradually decreases, or where the soil pressure gradually decreases due to changes in soil quality.

Under such construction conditions, the shield tunnel segment has the same inner diameter as that of a normal place and can be made thin, and when the segment is made thin, the excavation cross-sectional area and the segment diameter are reduced. As a result, the construction efficiency and construction cost can be significantly reduced.

However, in the parent-child shield machine disclosed in the above publication, although shield tunnels having different inner and outer diameters can be constructed, the inner diameter is the same and only the thickness can be reduced. There was also the problem of not being able to do it.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a parent-child shield excavator capable of simplifying a propulsion mechanism. is there.

Another object of the present invention is to provide a method for constructing a shield tunnel which has the same inner diameter and can be reduced in construction efficiency and construction cost by thinning only the thickness.

[0011]

In order to achieve the above object, the present invention is provided with a cutter for excavating the ground on the tip side, which is separably connected through a lock mechanism and has a different diameter. In a parent-child shield excavator in which child shields are concentrically arranged, the cutter is a cutter body that excavates a cross section that is substantially the same as the outer diameter of the child shield, and the cutter body is extendably provided on the side surface of the cutter body. Has a telescopic cutter that excavates a cross section that is approximately the same as the outer diameter of the parent shield in cooperation with, and uses the same propulsion mechanism for the parent and child shields as the same mechanism, and
Take the parent and child segments with the same inner diameter,
The thickness of the ment is thinner than the parent segment
I did . According to the parent-child shield excavator constructed in this manner, the propulsion mechanism for the parent and child shields is shared by the same mechanism, so that the structure is simplified and the portion to be buried and left in the ground is reduced. The locking mechanism includes a connecting jack that is provided on a child skin plate of the child shield and is capable of projecting and retracting in a radial direction, and a fitting recess that is provided on a parent skin plate of the parent shield and into which an expandable portion of the connecting jack is fitted. Can consist of: With this configuration, the parent and child shields can be easily separated by operating the connecting jack. In the parent-child shield machine of the present invention,
A seal portion interposed between the parent and child skin plates can be provided on the front side of the lock mechanism in the propelling direction. According to this configuration, it is possible to reduce the waterproofness between the parent and child shield skin plates and the friction between the skin plates when propelling the child shield. The parent-child shield excavator of the present invention can be configured by a hybrid system of muddy water or earth pressure system that is appropriately selected according to the soil condition. According to this configuration, a mud system or an earth pressure system can be selected according to the soil quality of the ground to be excavated, so that economical excavation can be performed according to the soil quality. Further, the present invention provides a shield using a parent-child shield excavator in which a cutter for excavating the natural ground is provided on the tip side, is separably connected through a lock mechanism, and parent and child shields having different diameters are concentrically arranged. In the construction method of the tunnel, when the child shield is separated from the parent shield and dug forward, the parent shield is assembled and installed at the end of the parent segment on the rear side of the parent shield,
A child segment having the same inner diameter as the parent segment and a small thickness is assembled and installed. According to the construction method of the shield tunnel constructed in this way, the child shield is separated from the parent shield and excavated at a place where the soil cover is gradually reduced, or where the soil pressure is gradually reduced due to a change in soil quality. At this time, a child segment having the same inner diameter as the parent segment and a small thickness is assembled and installed at the end of the parent segment that is assembled and installed on the rear side of the parent shield. It is possible to significantly reduce construction efficiency and construction cost. In the construction method of the present invention, the parent skin plate of the parent shield and the parent segment can be connected and fixed before the child shield is dug. With this configuration, it is possible to prevent the parent shield from moving when the child shield is dug or propelled. Further, in the construction method of the present invention, after the child shield is dug, an extension skin plate having a tail seal can be fixedly provided at the rear end of the child skin plate of the child shield. With this configuration, it is possible to avoid lengthening the child shield installed in the parent shield.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1 and 9 show one embodiment of a parent-child shield machine and a shield tunnel construction method using the machine according to the present invention.

The parent-child shield machine 10 shown in FIG.
It has a hybrid system structure of muddy water or earth pressure system that is appropriately selected according to the soil condition. The parent-child shield machine 10 includes a parent shield 12 and a child shield 14 which are concentrically arranged.

The parent shield 12 has an empty cylindrical parent skin plate 12a with both ends open, and a tail seal 12b provided on the inner periphery of the parent skin plate 12a on the rear end side.

The child shield 14 has a child skin plate 14a whose both ends are open. The child skin plate 14a has an outer diameter smaller than the inner diameter of the parent skin plate 12a, and the entire length is longer than that of the parent skin plate 12a. Is also getting shorter.

A cutter 16 for excavating the natural ground is provided on the tip side of the child skin plate 14a. Details of the cutter 16 are shown in FIG. The cutter 16 shown in the figure includes a disk-shaped cutter body 16a and a telescopic cutter 16b.

On the front surface of the cutter body 16a, cross-shaped spokes 160a and a plurality of face plates 161a provided between the spokes 160a are arranged.
In the meantime, the intake 162a for excavation is provided with the cutter body 16
It is provided so as to penetrate through a.

A center bit 163a is provided at the center of the spoke 160a, and a plurality of cutter bits 164a are fixedly provided on the front and side surfaces of the spoke 160a.

The telescopic cutter 16b is a spoke 160a.
Spoke 1 with a cutter bit on the side like
A cylinder 160b is provided so as to be retractable along the radial direction from the outer surface of the 60a, and a cylinder 160b for retracting the telescopic cutter 16b is incorporated inside the spoke 160a.

On the rear side of the cutter 16, a partition wall 18 having an outer peripheral edge fixed to the inner surface of the child skin plate 14a is provided.
The rotary shaft 20 provided on the rear side of the cutter 16 is rotatably supported by the partition wall 18.

The partition wall 18 is installed on the rear surface side of the cutter 16 with a predetermined space therebetween, and a partition chamber 22 is provided between them.
This compartment 22 defines the intake 16 for the excavated shear.
It communicates with 2a.

A rotary drive mechanism 24 for the cutter 16 is arranged on the partition wall 18. This rotary drive mechanism 24
In the case of the present embodiment, is used as both the parent and child shields 12 and 14, and is hydraulic or electric motor 24.
a, a speed reducer 24b, and a gear 24c.

The gear 24c connected to the rotary shaft of the hydraulic motor 24a is geared with the gear provided on the rotary shaft 20, and when the hydraulic or electric motor 24a is driven, the cutter 16 is rotated. There is.

In the cutter 16 constructed as described above, when the telescopic cutter 16b is projected from the side surface of the spoke 160a and the cutter 16 is rotated to excavate,
As indicated by the phantom line, the cross-sectional area that is substantially the same as the outer diameter of the parent skin plate 12a of the parent shield 12 is excavated by the cooperation of the cutter body 16a and the telescopic cutter 16b.

Further, when the cutter 16 is rotated and excavated while the telescopic cutter 16b is contracted, a cross-sectional area approximately the same as the outer diameter of the cutter body 16a is excavated, and this cross-sectional area is the child skin plate of the child shield 14. It has almost the same size as the outer diameter of 14a.

Further, the partition wall 18 is provided with a mud feed pipe 26 which penetrates the partition wall 18 and communicates with the inside of the compartment 22, a drainage pipe 28 and a screw conveyor 30. Sending and draining pipe 2
6, 28 are used when the parent-child shield machine 10 of this embodiment is used as a mud system, and the screw conveyor 30 is used.
Is used when the parent-child shield machine 10 of this embodiment is used as an earth pressure system.

The portion indicated by the reference numeral 32 in FIG. 1 is an erector for assembling the segment, and the portion 34 is a center-folded jack. The propulsion mechanism of the parent and child shields 12 and 14 of this embodiment is a propulsion jack 3 which is also used in these parts.
It is composed of 6. The propulsion jacks 36 are provided at predetermined intervals along the circumferential direction, and are supported by the skin plate 14 a of the child shield 14.

On the rear end side of the propulsion jack 36, there is provided a thrust distribution plate 40 which comes into contact with segments 46 and 56 described later and receives a reaction force. The parent skin plate 12a of the parent shield 12 and the child skin plate 14a of the child shield 14 are configured to be separable via the lock mechanism 42.

Details of the lock mechanism 42 are shown in FIGS. Although only one lock mechanism 42 is shown in the figure, a plurality of lock mechanisms 42 having the same configuration are arranged at predetermined intervals along the circumferential direction of the skin plates 12a and 14a. ing.

The lock mechanism 42 shown in FIGS. 6 and 7 is a connecting jack 42a provided on the child skin plate 14a side.
And a fitting portion 42b of the connecting jack 42a provided on the parent skin plate 12a side.

The connecting jack 42a is mounted in the mounting hole 14b formed in the child skin plate 14a and expands and contracts toward the parent skin plate 12a.
It has c.

The fitting portion 42b is a hollow cylindrical member into which the expansion / contraction plunger 42c of the connecting jack 42a is fitted.
A plurality of connecting jacks 42a are provided corresponding to the arrangement state of the connecting jacks 42a.

The fitting portion 42b has an outer end side fixed to the parent skin plate 12a and an inner end abutting the child skin plate 14a, and also has a function of maintaining a gap between the parent and child skin plates 12a, 14a. There is.

A seal portion 44 is provided on the front side of the lock mechanism 42. The seal portion 44 is annular and has an outer peripheral end fixed along the inner peripheral surface of the parent skin plate 12a. The inner peripheral end side slides along the outer peripheral surface of the child skin plate 14a. Touching.

The seal portion 44 is composed of the parent and child skin plates 1
It has a water stopping property in which outside water enters the inside of the parent-child shield excavator 10 after passing between 2a and 14a. Next, a method for excavating the parent-child shield machine 10 having the above-described configuration and a method for constructing a shield tunnel will be described.

When the parent-child shield machine 10 is dug under normal construction conditions to construct a shield tunnel, first, as shown in FIGS. 1 and 6, the connecting jack 42a of the lock mechanism 42 is operated to Parent and child skin plate 12
A and 14a are dug in a coupled state.

At this time, the cutter 16 extends the telescopic cutter 16b and rotationally drives it by the hydraulic motor 24a to excavate a cross-sectional area of approximately the same size as the outer diameter of the parent skin plate 12a.

The excavated earth and sand are taken into the compartment 22 and mixed with the muddy water sent through the mud pipe 26, and the mixture pressure is applied from the inside of the compartment 22 while facing the face pressure due to the pressure of the mixture. A part is discharged to the outside through the sludge pipe 280.

In this embodiment, excavation under construction conditions suitable for a muddy water shield operates as a muddy water system, so the screw conveyor 30 is closed by a gate jack.

As the parent-child shield excavator 10 excavates, a parent segment 46 is annularly assembled on the rear end side of the parent skin plate 12a, and the assembled segments 46 are sequentially connected in the axial direction to construct a tunnel. To do.

At the end of the assembled segment 46,
The thrust distribution plate 40 is sequentially brought into contact with the parent segment 46, and a reaction force is applied to the parent segment 46 to expand and contract the propulsion jack 36, whereby the parent-child shield excavator 10 continues to be excavated.

The thickness of the parent segment 46 is set to a size capable of withstanding earth pressure by adding the tail clearance and the thickness of the parent skin plate 12a to the inner diameter required for the shield tunnel.

When the excavation of the parent-child shield excavator 10 in the mud system as described above progresses and reaches a place where the soil cover is gradually reduced or a soil pressure is gradually reduced due to a change in soil quality, the excavator 10 is reached. And the child shield 14 is separated.

In separating the child shield 14, as shown in FIG. 2, first, the propulsion jack 36 is contracted to provide a space between the thrust distribution plate 40 and the parent segment 46.

When the child shield 14 is separated, as shown in FIG. 7, the connecting jack 42a of the lock mechanism 42 is operated to disengage the telescopic plunger 42c from the fitting recess 42b. Promote.

When propelling the child shield 14, as shown in FIG. 8, the thrust distribution plate 40 and the parent segment 46 are arranged.
The temporary reaction force material 48 is inserted into the space provided between the and.

The temporary reaction force member 48 is a beam member or a liner member having an axial force required for the machine thrust, and a member having the same structure as the parent segment 46 is assembled into an annular shape and used. At this time, the parent skin plate 12a and the parent segment 46 are connected and fixed by the fixing member 50.

One end of the fixing material 50 is provided with the parent skin plate 1
It is fixed to the inner surface of 2a by welding or the like, and the other end side is connected to the temporary reaction force member 48 and the parent segment 46 using a bolt box provided in the parent segment 46.

The fixing member 50 connects the parent skin plate 12a and the parent segment 46 before propelling the child shield 14 so that the parent shield 12 moves together when propelling or digging with the child shield 14. Prevent that.

After the provision of the temporary reaction force material 48 and the connection by the fixing material 50 are completed, as shown in FIG.
The excavation is started. At the time of this excavation, the mud pipes 26 and 27 are removed.

In this case, the parent and child skin plates 12a,
Since only the fitting concave portion 42b of the lock mechanism 42 and the seal portion 44 are interposed between the 14a, the circumferential surface friction acting between them is significantly smaller than that in the case of contacting the entire circumference.

When excavating the child shield 14, the cutter 16 is used.
The telescopic cutter 16b is reduced, and the cutter body 16
With a, excavation is performed with a cross-sectional area approximately the same as the size of the child skin plate 14a.

The excavated earth and sand taken into the compartment 22 is sequentially discharged part by part by the screw conveyor 30 while preventing collapse of the cutting face. The excavation of the child shield 14 is
The thrust force distribution plate 40 is brought into contact with the temporary reaction force member 48 to expand and contract the propulsion jack 36.
When the digging is performed for a distance corresponding to the length, the digging is temporarily stopped, the temporary reaction force material 48 is removed, and the child skin plate 14a is removed.
An extension skin plate 52 is fixedly installed on the.

As shown in detail in FIG. 9, the extension skin plate 52 has the same diameter as the child skin plate 14a, and a tail seal 54 is annularly provided on the inner peripheral surface of the rear end.

The length of the extension skin plate 52 is less than twice the jack stroke of the propulsion jack 36, which in this embodiment is about twice the length of the child segment 56. .

Therefore, in the case of this embodiment, the child shield 14 uses the temporary reaction force material 48, and after excavating a distance corresponding to two rings of the child segment 56, the child shield 14 is stopped and the extension plate 52 is used. Will be fixed.

The length of the extension skin plate 52 is
The provisional reaction force material 48 is not limited to two rings, but may be one ring as a matter of course. In this case, the tail seal 12b of the parent skin plate 12a is in sliding contact with the outer peripheral surface of the parent segment 46, and the parent and child skin plates 12a,
Since the seal portion 44 is interposed between 14a, it is possible to prevent the intrusion of external water while the child skin plate 12a is in contact with the seal portion 44.

When the extension skin plate 52 is fixed to the child skin plate 14a, the child segment 56 is assembled and installed in an annular shape at the portion where the temporary reaction force material 48 is removed.

The child segment 56, as shown in FIG.
It has the same inner diameter as the parent segment 46 and is thin. The reduction amount of the thickness of the child segment 56 corresponds to the reduction amount of soil cover and earth pressure.

Thereafter, the child shield 14 is excavated by the earth pressure system, and the child segments 56 are sequentially assembled and installed on the rear side of the extension skin plate 52 to construct a predetermined shield tunnel.

According to the parent-child shield excavator 10 configured as described above, the propulsion mechanism (propulsion jack 36) for the parent and child shields 12 and 14 is also used as the same mechanism.
The structure is simplified, and only the parent skin plate 12a and its accessories are left to be buried and left in the natural ground, which is extremely small.

Further, in the case of the present embodiment, the lock mechanism 4
2 includes a connecting jack 42a which is provided on the skin plate 14a of the child shield 14 and which can be retracted in the radial direction, and a fitting recess 42b which is provided on the skin plate 12a of the parent shield 12 and into which the expansion / contraction portion of the connecting jack 42a is fitted. Since it is configured, by operating the connecting jack 42a,
The parent and child shields 12 and 14 can be easily separated.

Further, in the case of this embodiment, the lock mechanism 4
2, the parent and child skin plates 12 on the front side in the propulsion direction
Since the seal portion 44 is provided between the a and 14a, the waterproofness between the parent and child skin plates 12a and 14a and the friction between the skin plates 12a and 14a when propelling the child shield 14 are prevented. It can be reduced.

Further, in the case of the present embodiment, since the parent-child shield excavator 10 is constituted by a mud water or earth pressure system hybrid system which is appropriately selected in accordance with the soil condition,
A mud system or an earth pressure system can be selected according to the soil quality of the ground to be excavated, and economical excavation can be performed according to the soil quality.

On the other hand, according to the construction method of the shield tunnel of the present invention, the child shield 14 is separated from the parent shield 12 at a place where the soil cover is gradually reduced or the soil pressure is gradually reduced due to the change of soil quality. When excavating, the parent segment 4 assembled and installed on the rear side of the parent shield 14
Since the child segment 56 having the same inner diameter as the parent segment 46 and having a small thickness is assembled and installed at the end of 6, the construction efficiency and the construction cost can be significantly reduced by reducing the excavation cross-sectional area and the diameter of the child segment 56. Will be possible.

In the construction method of this embodiment, the skin plate 1 of the parent shield 14 is cut before the child shield 14 is dug.
Since 4a and the parent segment 46 are connected, the parent shield 12 can be prevented from moving together when the child shield 14 is dug.

Further, in the construction method of this embodiment, after the child shield 14 is dug, the extension skin plate 52 having the tail seal 54 is fixedly provided at the rear end of the skin plate 14a of the child shield 14, so that the parent shield It is possible to avoid lengthening the child shield 14 installed inside 12.

[0068]

As described above in detail in the embodiments,
According to the parent-child shield machine of the present invention, the propulsion mechanism can be simplified, and the construction method of the shield tunnel using the machine can significantly reduce the construction efficiency and construction cost. .

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a parent-child shield excavator according to the present invention.

FIG. 2 is a vertical cross-sectional view of a state in which a child shield is propelled by the parent-child shield excavator of FIG.

3 is a vertical cross-sectional view showing a state in which an extension skin plate is fixedly attached to the child shield of FIG.

FIG. 4 is a vertical cross-sectional view of the child shield in the excavated state of the parent-child shield excavator shown in FIG. 1.

5 is a front view of a cutter of the parent-child shield excavator of FIG. 1. FIG.

FIG. 6 is an enlarged view of part A in FIG.

FIG. 7 is an explanatory view showing a state in which the parent and child shields are separated by the parent-child shield excavator of the present invention.

FIG. 8 is an enlarged view of part B in FIG.

9 is an enlarged view of a C portion of FIG.

[Explanation of symbols]

10 shield machine 12 parent shield 12a Parent skin plate 12b Parent tail seal 14 child shield 14a Child skin plate 14b Mounting hole 16 cutter 16a cutter body 16b telescopic cutter 24 rotation drive mechanism 24a hydraulic motor 36 Propulsion mechanism (propulsion jack) 42 Lock mechanism 42a connection jack 42b Mating recess 44 Seal part 46 Parent segment 52 Extended Skin Plate 56 child segments

Front page continuation (72) Inventor Kimiaki Sakamoto 1-1-1 Otani, Hirakata-shi, Osaka Prefecture Obayashi Osaka Machinery Factory (72) Inventor Yoshisuke Yamagiwa 1-1-1 Otani, Hirakata-shi, Osaka Prefecture Obayashi Osaka Machinery Factory (72) Inventor Koji Noguchi Invited by Hirakata, Osaka 1-1-1 Otani Obayashi Osaka Machinery Factory (56) Reference JP-A-5-10086 (JP, A) JP-A-10 -37659 (JP, A) JP-A-8-210081 (JP, A) Actual development Sho 57-197594 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21D 9/06 301 E21D 9/08

Claims (7)

(57) [Claims] 1. A parent-child shield excavator in which a cutter for excavating a natural ground is provided on the tip side, which is separably connected via a lock mechanism and in which parent and child shields having different diameters are concentrically arranged, Is a cutter body for excavating a cross section that is substantially the same as the outer diameter of the child shield, and is provided on the side surface of the cutter body so that it can expand and contract. It has a telescopic cutter for excavating, and uses the same propulsion mechanism for the parent and child shields as the front mechanism.
The parent and child segments that take the reaction force of the propulsion mechanism are the same.
At the inner diameter, the thickness of the child segment is
Parent-child shield excavator characterized by being extremely thin . 2. The locking mechanism is provided on a connecting jack provided on a child skin plate of the child shield and capable of projecting and retracting in a radial direction, and a parent skin plate of the parent shield, and a telescopic portion of the connecting jack is fitted therein. The parent-child shield excavator according to claim 1, wherein the parent-child shield excavator has a fitting recess. 3. The parent-child shield excavation according to claim 1 or 2, further comprising a seal portion which is located on a front side in a propelling direction of the lock mechanism and which is interposed between the parent and child skin plates. Machine. 4. The parent-child shield excavator according to claim 1, wherein the parent-child shield excavator is a hybrid system of muddy water or earth pressure system which is appropriately selected according to the soil condition. Shield machine. 5. A shield tunnel using a parent-child shield excavator in which a cutter for excavating the natural ground is provided on the tip side, is separably connected through a lock mechanism, and parent and child shields having different diameters are concentrically arranged. In the construction method of, when the child shield is separated from the parent shield and dug forward, the parent segment is assembled and installed on the rear side of the parent shield at the end of the parent segment, the inner diameter of which is the same as that of the parent segment A construction method of a shield tunnel using a parent-child shield excavator characterized by assembling and installing thin child segments. 6. The method for constructing a shield tunnel using a parent-child shield excavator according to claim 5, wherein the parent skin plate of the parent shield and the parent segment are connected and fixed before the child-shield excavation. 7. The parent-child shield excavator according to claim 5, wherein an extension skin plate having a tail seal is fixedly provided at a rear end of the child skin plate of the child shield after the child shield is dug forward. Construction method of shield tunnel using.